Endophyte-infected diet alters gene expression in heifer luteal tissue

Gene expression analysis in heifer luteal tissue by interspecies microarray analysis. Post-pubertal heifers were fed diets containing endophyte free fescue seed (EF), endophyte infected fescue seed (EI) or EI seed supplemented with 1.44 mg domperidone/kg body weight (EID). One heifer from each treatment group was slaughtered at a local abattoir 11-14 days after ovulation (EF = 11d, EI = 14d and EID = 14d ) and used for this study. Ovaries were collected and shipped at room temperature to the laboratory. Approximately 3 mm3 samples of luteal tissue were placed in cryovials and frozen at -80°C until processed. One 3 mm3 sample each for the EI and EID treatments and two samples for the EF treatment were ground to a fine powder in liquid N and total RNA was extracted using the RNeasy® Mini Kit (Qiagen, Valencia, CA). Quality and quantity of RNA was determined by gel electrophoresis and spectrophotometry. Five µg of total RNA was converted to cDNA and then biotin-labeled cRNA by linear amplification (CodeLink® Expression Bioarrays, Amersham Biosciences Corp, Piscataway, NJ, USA). Ten micrograms of labeled cRNA were hybridized to CodeLink UniSet Rat I Bioarray (Amersham Biosciences Corp, Piscataway, NJ, USA) by the Amersham Biosciences Facility. Keywords: other